


Starlight

by shadowarchives



Series: The Undertale Trilogy (Untold Episodes) [2]
Category: Undertale (Video Game)
Genre: Based on the heaven fell hatred effects, Set after last promise
Language: English
Status: Completed
Published: 2017-12-20
Updated: 2017-12-30
Packaged: 2019-02-17 12:32:17
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 5
Words: 2,770
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13076949
Author URL: https://archiveofourown.org/users/shadowarchives/pseuds/shadowarchives





	1. Last corridor

You were able to take it easy once you were fully healed. Thanks to Sans and Gaster's Serifim formula you seemed to be back to normal. However the work down at the underground wasn't over. 

A specific order was given out by the human and monster leaders to remove everything from the underground. This included all the save points, and being the most able to person to take this task. Sans went down to find them. The cave was only accessible during a certain time of day. When it became nighttime the cave would shut. But something was wrong. Sans seemed to be taking longer than normal. So you went out to go and find him in the evening. You found your way into the last corridor to find him staring at the Save star. "Hey kid... Remember this, heheheh. The last one here. All the others bit the dust, so now I just need to destroy this one." Sans tries to slice the star open. But it doesn't break. "What? what's going on." Sans looks confused "I don't know, it doesn't seem to want to break open." Sans eventually had an idea and charged up a gaster blaster to destroy the star but to no avail

~Determination

The skeleton kept on charging more blasters, each one increasing the power of the attack

~The will to live on

"Sans, something isn't right here."

~The will to survive after death and choose your own fate

"I must destroy it!"

~There are two types of determination most commonly found in Red souls

Sans' attack eventually gets charged by his inner determination

~Mercy...

"Wait Sans. Stop! It's gonna-"

~And HATE!

You have no time to react as the two of you surrounded in a white light. The star shatters into a million pieces and you are knocked unconscious. Your limp body is inflicted by the shards as they explode like fireworks. The two of you pass out and everything goes quiet

~...And monster... They have a lot to share...

 

Sans is the one to wake up first. He is stunned by the light but sees that the star is gone. He grins and sighs on relief "Finally it's ERASED. Hey Frisk you ok?" You can't respond as you are face down on the ground. Unable to move and gasping for the release of the immense amount of pressure on you. Your body is completely covered in Black scars and the clothing you wore to the mountain has changed to black and red. Sans rushes over to you to check on you. "Frisk. Kid, are you alright." He rolls you over slightly to see your covered in the black marks that lie on your body.

"I-I c-can't m-m-move... W-What's h-happ-pening-g t-to me-e?!"

Sans face of happiness turns to immediate dread when he hears that the entrance to the cave has been put under lockdown for the night. No teleportation was gonna get him out of the underground yet.

"Hold on kid. We're gonna have to go further into the underground... Up we go." Sans carefully lifts you into his arms with one hand carrying your aching limp body and the other hold your legs. "I know where the best place is to stay... New home..." Sans hurries along the capital pathways and turns the key to the houses' door.


	2. A fallen Star

"Hey Tori. It's me Sans... I'm currently in the underground with Frisk at the moment. She appears to be sick for some reason that I'm trying to figure out... I remember destroying a Save star with Frisk near me and then nothing else after that. I hope you get this message and I'll chat with you in the morning. See you soon."

Sans puts down the phone and picks up the small blood sample that he had of Frisk, as well as a new sample he took from today. He checked them both and found that she was being affected by a different type of determination. He remembered what Chara said to him about Hate and Mercy, so he could only come to one conclusion. That frisk was being attacked by hate bottled up in that Save star.

He leaves the samples and decides to check on Frisk again. She was lying down on the bed, still weak from the effects that the Hate inflicted on her.

"Hey kiddo. You ok." Sans asks. Frisk gives a small nod and tries to get up but fails. Sans rubs the back of her head to keep her calm. "It's ok. Save your energy... I need to tell you something." Frisk gradually sits up properly and gives Sans some space to lie down next to her. They were in Asgore's room in the New home whilst they spent that night in the underground. "S-sure." Frisk says shakily whilst Sans gets on the bed and sits next to her.

"Remember that, time. We had in the Judgement hall... Well I found out from Gaster that when you and I fought. The determination affected many things in that world, including the Save star... And it appears that my determination has leaked into the save star. changing how it affects the people in that location." Frisk seems to understand. "Ok, I think I understand." Sans gives a contended sigh and continues on. "But the problem here, is that there are two types of Determination. There is Mercy which is what you are familiar with. And then... There's Hate."

Frisk suddenly realised that her actions had caused Sans to hate her. And this was her becoming inflicted by her past mistakes.

~You feel your sins crawling all over your soul.

"Oh god... S-Sans I-I... I n-never knew t-that." Frisk started to become teary eyed and Sans pulled her into a hug. "Hey, hey, kid. Kid. It's alright. I never knew either... It's ok... It wasn't your fault... It was my fault. I was the one fuelling the Save star...You're not in the wrong here..." Frisk sobbed into Sans jacket in pain and guilt. "I n-never knew that. This w-would happen... Oh god, Sans I'm sorry... I'm so sorry!" 

Sans held her closer as her cries started to become no more than teary hiccups. "It's alright Frisk, you have nothing to be sorry for... I just wish I had known sooner that this was the case... I should've known when I saw your soul." Sans gently raked his phalanges through her hair as her breathing started to slow and her pulse started to drop again. The occasional Sob and sniffle still broke through but generally she had calmed down. Too weak the get up and too tired to move properly. She just stayed there with the skeleton monster.

"It's ok Frisk. I've got you... You're safe here." Sans said cuddling the little human as she cornered into his caring embrace, Longing any affection and comfort he had. Sans smiled a calm and peaceful smile. Even more calmer than his usual expression as he sat there silently. With the occasional quiet "Shhhh" as Frisk slowly started to fall asleep. He looked at the door as he comforted the child from their weakened state. He figured he wouldn't be out of here by tomorrow. This was going to take some time to fix.


	3. Antidote of emotions

Sans was looking up through the hole where the sunlight was shining through. He had a lot on his mind about Frisks condition

(“God I can’t believe it, it’s all my fault she is suffering.”) He remembers every Gaster blaster that ripped through her flesh and spat out blood (“ all this pain and anger she is experiencing...”) Every Gaster blaster that swallowed up her soul (“...Why, Why didn’t it become inflicted onto my soul!”) every hurtful comment against a kid that lost control. (“I feel disgusting, hollow, fractured. I feel so lost!”)

“I don’t understand, I can’t understand. I just can’t understand!” Sans suddenly lashes out. His left eye flares up and explodes from his head. The light burning in anger as he lets his fury out of himself... he calms down and tears start falling from his eyes as he looks at the golden flowers below him.

(“Sometimes taking the high road is a painful task Sans. But she will heal with time, and as she heals. You will understand that her suffering is not in vain.”) 

Gasters thoughts emerge in his head as he heads back to the new home. Frisk has been able to walk the next morning but the scars weren’t disappearing. 

“Frisk I’m sorry, I’m so sorry... Please forgive me...”

When he came back into the staircase room he saw the Frisk was lying on the floor. It appeared that she was in pain and patches of blood were near her head. Was this what Gaster was talking about. Sans rushed up the stairs and ran over to the shaking human. Levering her back so that she was sitting up and avoiding the risk of choking as blood was coughed up and splattered onto the back of his jacket.

But her protector didn’t mind and he just held her steadily, crying and fearing for her life. Worried that she would slip from this world. “Hey, it’s ok Frisk. I’m still here, I’m still here.” Frisks sobs are all that is heard in the house “...Sans...Sans help me...” Is all she can properly word as her throat is becoming raspy and irritated from the blood. Sans lifts her up and carries her into the house’s bedroom they were in before. Grunting a little bit from her small yet surprisingly hefty stature.

“It’s not your fault Frisk, it’s just a little bit of blood. Nothing that can’t be cleaned away.” Sans says as Frisk coughs more blood onto his jacket that spills onto his white shirt. He gently pets the humans head as sits down on the bed and places the kid beside him as she weeps in fear and pain. “Sans...” she says in between coughing fits of red liquid. “I feel like I’m going to die... please tell me I’m not...” Sans opens his arms out and frisk curls into his lap and sobs wrack her body. “Of course you won’t Frisk. I’ll stay with you as long as you need and help you get better.” Frisks lips were painted red from the liquid but the blood seemed to lessen up.

Sans held his arms around her protectively, he knew that she wouldn’t heal unless he showed her care and love to counteract the hate flowing through the cuts in her fragile body. Gaster was right about his theory to reduce the hate scars. Frisk hugged her friend seeking much needed comfort as her sobs started to lessen. Sans looking down at her affectionately and kept his arms around her, petting her gently and caringly. “It’s Alright Frisk. You don’t have to be scared. I’m right here.” Sans purred as Frisks breathing returned to normal. “Thank you Sans... Please don’t leave.” 

Sans carefully raked his fingers through her dark hair, rubbing any stray hairs from her forehead as she fell asleep. Cradling her as if she were his child. His sibling... He remembered the promise he made to her back underground. Frisk was part of his and Papyrus’ family, and he wouldn’t let that slide now. Sans looked at the artwork on the wall. The glass covering it reflected his image. 

~ Despite all that you’ve been through, it’s still you.

Sans smiled as he heard the quiet sniffles of Frisks steady breathing, It was late in the evening and she would feel a lot better in the morning.  
“Stay determined, Frisk”

Sans too drifted off to sleep

(“My little human.”)


	4. Morning sun

Sans had a bit of a rough night, he kept on having these bad dreams again about his family. But he was still able to get some sleep as he eventually woke up in the early hours of morning, small black lines under his eyes to signify his lack of sleep.

He picked up from where he was last night and looked down to see his little human burying their face in his jacket. More blood must’ve been coughed out as Sans’ shirt ranged from white to a dark yet not quite crimson red colour. “Damn, that’s a lot of blood... Poor thing... It’s ok, Sans is here” The kid was fast asleep with their arms around Sans, still trying to garner as much comfort as possible from their horrific condition.

But Sans didn’t mind. The child felt oddly comforting in his lap and he didn’t leave to the other room when Frisk fell asleep. He instead stayed with her the whole night and protected her from harm. When he heard Frisk make a small yet audible whimper, Sans smiled and looked down at her. Whispering “Don’t worry kid, I’m not gonna fail you now.” He rested his head on the child’s soft hair, slowly and gently leaning from side to side as she rested in a curled up position.

“I’m proud of you buddy, I’m so proud of you. You’ve kept us all with a hope that has never died, when all others had passed away... I honestly don’t know how much I owe you anymore.” 

Sans grinned dreamily as he felt Frisk starting to wake up, gently petting her as she rested her head to the side. “S-Sans?” Sans looked down at the child “Yeah kid?” Frisk sounded very tired from all the recovering she had to do over the past months. First her mending soul from Chara, and now this... Kid needed a break.

“I’m sorry for what happened yesterday. I didn’t realise that I was still pretty weak and the healing would cause this.” Sans knew she meant the blood, honestly it was a little bit gruesome. But he just wanted to take care of her and protect her. “It’s alright kid, I wanted to make sure you were safe. Besides, it’s not like I wear these clothes a lot. Papyrus is getting a bit bone-tired from it. Heheh.” 

Frisk chuckles at Sans pun, her head resting on his rib cage. “Hey Sans, i never asked you this before but. What was your life like before the war.” Sans chuckled at the interesting question. “You are a funny child huh kid. It was pretty good, I didn’t have too much troubles but that was because I stayed out of peoples ways most of the time. I didn’t make very good friends before on the surface.” 

Frisk looked up at him with a smile on her face. “It’s ok. You have great friends now that we’re back on the surface, so I guess it all turned out. Besides me and Papyrus will always be your friends.” “Heheh, thanks kid... I’ll be there for you as well, I’ve been there since day 1 and I ain’t leaving you now.” Sans gently strokes her dark hair, obviously enjoying that she was able to spend time with him. He never had that on the surface before the war. “Promise?” Sans nods “I promise kid, I’m always watching over you... I love you Frisk, remember that.” Frisk smiled as she cuddled up into his caring embrace “thanks. I love you too.” 

Sans carefully tipped his head down and gently pecked her forehead in the approximation of a kiss... he looked at her soul to see that it was all better. “C’mon, lets go back to the surface.” Sans whispered to her as he lifted her up. Her appearance was back to normal as reflected in the hallways mirror. Sans turned off the new homes house lights and headed to the stairs... he looked at the calendar that marked 201X, it would be New Year soon. And their lives would change even then... but their hearts would always be as one, as the underground family.


	5. The only limit is the sky

Sans walked back through caverns of new home and made it back to the concealment area of the underground. He carried Frisk who’s hands were wrapped round his shoulders, her head resting on his left shoulder. He looked at the light shining through the barrier and knew that the door would open in that moment.

And so it did as the magic door opened and the guards of the mountain escorted them back on the cliff top. Sans made his way down to the bottom where Papyrus and Toriel were waiting. 

“Brother! Where have you been!?”

“We were so worried, are you two alright?” 

Sans heard The two of them say. He sighed and looked at Frisk. She grinned happily at him and Sans chuckled, “hyeah. We’re alright, let’s head home again.”


End file.
